Currently the best-known virtual network in which virtual addresses are used is the internet protocol network or IP network. In an IP network, i.e. in a network that uses the TCP/IP protocol, each item of network equipment up to the terminal unit requires a unique virtual address, the internet protocol address or IP address. An IP address that is generated from a network address and a device address comprises, in IP Version 4 (IP v4), four numbers (octets) that are separated by a full stop, e.g. 75.214.64.x. In later IP versions, more octets are used for IP addresses. IP addresses can be generated manually and permanently assigned to items of network equipment including the terminal units in a network. The IP address for an item of network equipment is required to transmit information via the internet protocol specifically to this item of network equipment. Manually configuring IP networks is, however, time consuming and only of interest for small subnetworks that are seldom changed.
To automate IP address assignment, network operators usually therefore use a bootstrap protocol BOOTP or a dynamic host configuration protocol DHCP. BOOTP is a TCP/IP protocol that can be used by items of network equipment to determine their IP address or other network information such as server addresses and gateway information. When an item of network equipment is started, a boot request query is sent in a UDP packet (user data protocol, an non-reliable protocol from the TCP/IP protocol suite) to the BOOTP server that returns the required IP address with a boot response message. The boot request and boot response messages use an IP broadcast function, which can be used to send messages before the specific IP address is known. Such a method is described in detail, for example, in U.S. Pat. No. 6,115,545.
DHCP is another software program for automatically assigning IP addresses to items of network equipment that log into a TCP/IP network. DHCP software usually runs on servers and such a DHCP server is, for example, described in U.S. Pat. No. 5,884,024.
To issue an IP address, BOOTP servers or DHCP servers require a hardware address of an item of network equipment that is transmitted from the network interface of this item of network equipment in the IP address query message, such as the boot request, to the appropriate server.
In networks operating on the Ethernet standard, the hardware address (MAC address) of the Ethernet card forming the subscriber-side network termination unit at a network interface in bus structure data networks is used as a uniquely assignable identifier for each IP address query and IP address reply (boot request, boot response).
In telecommunications networks that are part of an IP network, a hardware address of a subscriber-side network interface of an item of network equipment is mostly used as a uniquely assignable identifier for each IP address query and IP address reply (boot request, boot response) of this item of network equipment. Such a pseudo-hardware address on the subscriber side need not necessarily be assigned to the terminal array, but instead may because of the additional effective transmission technology in the telecommunications network be assigned to the subscriber line or a subscriber-side network terminal unit. If on the subscriber side of such a network termination unit, several termination units are each connected via a separate telecommunications interface, then each of these requires an individual IP address.
Such a network termination unit in a telecommunications network that terminates an IP network on the subscriber side of the subscriber line of a telecommunications network, is used to multiplex different communication technologies on the subscriber side on an individual telecommunications network connection and to de-multiplex the data streams coming from the network into the associated channels. Such network termination units are often referred to as integrated access devices or IADs. A telecommunications network connection to connect an IAD can be an analog telephone connection, an ISDN connection, a DSL connection or a T1 connection. An IAD can also be part of a private branch exchange that provides a number of ISDN S0-bus connections or POTS subscriber line units on the subscriber side. Such private branch exchanges (PBXs) are also known as switches. Currently, IAD units are most commonly used to multiplex voice and data via a DSL connection. DSL denotes a digital subscriber line that is not activated as an ISDN connection using switching technology, but is permanently connected and supplied with voice information and data information via a central item of network equipment, a DSLAM (DSL Access Multiplexer). The digital subscriber lines (DSL) of a particular local area go out from such a DSLAM that is usually part of a peripheral network node. A specific subscriber line data record (port data) is often stored for each subscriber line in the DSLAM and configured by central network management.
Network operators can, for example, use SNMP over IP to centrally manage items of network equipment such as DSLAMs or IADs in an IP network. SNMP stands for Simple Network Management Protocol. This is a widely distributed network monitoring and control protocol. To manage an item of network equipment, the network operator must assign a static IP address to the associated network management interface that can be used to exchange network management messages. The IP router and the network management system within the IP network of the network operator must also know this IP address. Network operators use one of the BOOTP or DHCP protocols as mentioned above to achieve this, The unique identifier to set an IP address in a BOOTP server or DHCP server is usually the hardware address of the item of network equipment. The corresponding IP address, since it is also used for management purposes, is also known as the management IP address.
When setting up an item of network equipment, the network operator must enter the required information in the BOOTP server with the hardware address of the internet protocol interface of the appropriate network array of the item of network equipment used and its IP address to be assigned. For subscriber-side terminal units to be connected to an IAD unit by the subscriber via a telecommunication terminal interface such as a DSL connection, an ISDN S0-bus or a POTS subscriber line unit, either the exact hardware address of the terminal unit has to be entered manually by the subscriber before the unit is set up, or the subscriber has to register the hardware address by telephone or post with the network operator after the terminal unit has been set up at the subscriber premises. Often, IP terminal units are connected on the subscriber side via telecommunication interfaces such as ISDN S0-bus connections or POTS subscriber line units via an IAD unit and, for example, via a telecommunications network to an IP network. (POTS stands for Plain Old Telecommunication System and designates analog line telephony or data transfer in accordance with an analog line modem standard such as V.90). Currently, the only solution in such a case is for the subscriber to register the hardware address of the terminal unit. The two methods of registering that have been described are very labor intensive, require coordination between the subscriber and the network operator, are prone to errors and can lead to unacceptable delays in the availability of the service once the terminal unit has been installed at the subscriber premises. In addition, the subscriber has to register each individual terminal to be connected via such an S0-bus connection or such a POTS subscriber line unit with the central IP network management. Such a terminal unit might, for example, be an H.323 video telephone with a communications interface adapted for the subscriber line. It may also be a computer, a fax or an IP telephone with the appropriate communications interface.